//       Introduction to Java programming
//*****************************************************
// Once you've got Java on your system, the 
//quickest and best way to learn Java programming is
//to do Java programming. That's why this chapter 
//shows you how to write complete Java programs that 
//get input from a user, make calculations, and 
//display output. When you finish this chapter, 
//you should be able to write comparable programs of
//your own.
//*****************************************************
 
import java.util.Scanner;

public class InvoiceApp
{
    public static void main(String[] args)
    {
     //display a welcome message
     System.out.println("Welcome to the Invoice Total Calculator");
     System.out.print();    // print a blank line
 
     // get the input from the user
     Scanner sc = new Scanner(System.in);
     System.out.print("Enter subtotal:   ");
     double subtotal = sc.nextDouble();
     
     // calculate the discount amount and total
     double discountPercent = .2;
     double discountAmount  = subtotal * discountPercent;
     double invoiceTotal    = subtotal - discountAmount;

     // format and display the result
     String message = "Discount percent: " + discountPercent + "\n" 
                    + "Discount amount: " + discountAmount + "\n" 
                    + "Invoice total:  " + invoiceTotal + "\n";
     System.out.println(message); 
 
   }

  
}